A wide variety of human tricycles are commercially available. Tricycles typically follow three layouts. An upright tricycle resembles a two-wheel bicycle but with two wheels at the back and the rider straddling the frame. The upright tricycle is steered through a handlebar directly connected to the front wheel. A delta tricycle is similar to an upright tricycle, but has a recumbent layout in which the rider is seated in a chair-like seat, one or both rear wheels can be driven, while the front is used typically for steering. The delta tricycle is steered either through a linkage, with the handlebars under the seat or directly to the front wheel with a large handlebar. A tadpole, or a reverse trike, has a recumbent design with two steered wheels at the front and one driven wheel at the back. The tadpole trike is steered through a single handlebar linked with tie rods to the front wheel stub axle assemblies or with two handlebars each bolted to a steering tube, usually through a bicycle-type headset and connected to a stub axle assembly.
The main advantages of tricycles over a standard bicycle are stability and safety. The three wheels in a tricycle, instead of two, enables the rider to load extra weight on the tricycle, such as small children and/or shopping bags, and to maintain the child and/or bags on the tricycle without risk of falling, even when the tricycle is at a full stop. However, tricycles are quite large vehicles. Their large size makes it difficult to use them indoors, on busses, or on trains.
On the other hand, a stroller is convenient for transporting a child and/or a package in a confined space, such as an indoor location, a bus, or a train.
What is needed is a convertible cycling-stroller apparatus that combines the benefits of a tricycle with the benefits of a stroller.